A073216 - OEIS

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A073216

The terms of A055235 (sums of two powers of 3) divided by 2.

1, 2, 3, 5, 6, 9, 14, 15, 18, 27, 41, 42, 45, 54, 81, 122, 123, 126, 135, 162, 243, 365, 366, 369, 378, 405, 486, 729, 1094, 1095, 1098, 1107, 1134, 1215, 1458, 2187

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OFFSET

1,2

COMMENTS

n such that 3 is the largest power of 3 dividing binomial(3n,n). - Benoit Cloitre, Jan 01 2004

Equals A023745 + 1.

This sequence is A007051 together with its (successive) multiples by (powers of) 3. - R. K. Guy, Oct 08 2011

LINKS

Table of n, a(n) for n=1..36.

C. Armana, Coefficients of Drinfeld modular forms and Hecke operators, Journal of Number Theory 131 (2011), 1435-1460.

FORMULA

(3^n + 3^m) / 2, n = 0, 1, 2, 3 ..., m = 0, 1, 2, 3, ... n.